I've heard this works really well:
https://www.knitpicks.com/cfAccessor...mpaign=PPCGNBS
They say it gets out tobacco smoke from fabrics too....
I have never tried it.
my first mat had a smell when wet. It was minor, but I used a pressing sheet between it and my fabric anyway. I bought a second (24x72) wool sheet & cut it down. That one has no smell.
Google has several products you could try--some are homemade :
https://www.google.com/search?q=wool...nt=firefox-b-1